Interchangeable lens and camera body

ABSTRACT

An interchangeable lens includes: a mount unit on which a camera body can be mounted; a driven member; a drive unit that drives the driven member; a storage unit that stores lens data related to driving of the driven member by the drive unit; and a transmitter that sends lens-side judgment data, based on which whether the lens data is properly stored in the storage unit can be judged at the camera body, to the camera body.

This Application is a Divisional of U.S. patent application Ser. No.14/424,857 filed Feb. 27, 2015, which in turn is a National PhaseApplication of International Application No. PCT/JP2013/072281 filed onAug. 21, 2013, which claims the benefit of Japanese Patent ApplicationNo. 2012-191979 filed on Aug. 31, 2012, and Japanese Patent ApplicationNo. 2012-269590 filed on Dec. 10, 2012. The disclosure of each of theprior applications is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to an interchangeable lens and a camerabody.

BACKGROUND ART

Conventionally, an interchangeable lens capable of calculating aperturedrive time has been known with a camera system of a so-calledsingle-lens reflex type. For example, Patent Literature 1 describes aconfiguration in which a lens microcomputer in an interchangeable lenscalculates the aperture drive time based on aperture speed informationstored in an internal memory in advance and driving amount informationreceived from a camera microcomputer.

CITATION LIST Patent Literature

PATENT LITERATURE 1: Japanese Laid Open Patent Publication No.2006-208897

SUMMARY OF INVENTION Technical Problem

The conventional technology has a problem of the inability to properlycontrol driving of a driven member when information which is stored in astorage medium inside the interchangeable lens in advance is damaged dueto, for example, strong electric impacts.

Solution to Problem

An interchangeable lens according to a first aspect of the presentinvention comprises: a mount unit on which a camera body can be mounted;a driven member, a drive unit that drives the driven member; a storageunit that stores lens data related to driving of the driven member bythe drive unit; and a transmitter that sends lens-side judgment data,based on which whether the lens data is properly stored in the storageunit can be judged at the camera body, to the camera body.

According to a second aspect of the present invention, in theinterchangeable lens according to the first aspect, it is preferablethat the lens-side judgment data is generated based on the lens datastored in the storage unit.

According to a third aspect of the present invention, in theinterchangeable lens according to the first or second aspect, it ispreferable to further comprise: an estimation unit that estimates drivetime required for the drive unit to drive the driven member by a desireddriving amount at a desired drive speed based on the lens data stored inthe storage unit.

According to a fourth aspect of the present invention, in theinterchangeable lens according to the third aspect, it is preferablethat the transmitter sends the drive time estimated by the estimationunit as the lens-side judgment data to the camera body.

According to a fifth aspect of the present invention, in theinterchangeable lens according to the fourth aspect, it is preferablethat the lens data includes an operation expression to calculate thedrive time by using at least the desired drive speed and the desireddriving amount; and the estimation unit estimates the drive time bycalculation processing that uses the operation expression.

According to a sixth aspect of the present invention, in theinterchangeable lens according to the fifth aspect, it is preferablethat the lens data includes a simple operation expression to calculatethe drive time by using only the desired drive speed and the desireddriving amount; and the estimation unit estimates the drive time bycalculation processing that uses the simple operation expression.

According to a seventh aspect of the present invention, in theinterchangeable lens according to the fifth or sixth aspect, it ispreferable that the estimation unit calculates the drive time bychanging at least one of values of the drive speed and the drivingamount every time the calculation is performed.

According to an eighth aspect of the present invention, in theinterchangeable lens according to the fifth aspect, it is preferablethat the storage unit stores the lens data including at least one of theoperation expression of the drive time and correction term data given tothe operation expression of the drive time; and the transmitter sends atleast part of the correction term data as data related to the lens-sidejudgment data to the camera body.

According to a ninth aspect of the present invention, in theinterchangeable lens according to the fifth or sixth aspect, it ispreferable that the estimation unit calculates a plurality of drivetimes by executing the calculation processing to calculate the drivetime every time the estimation unit receives a combination of thedesired drive speed and the desired driving amount; and the transmittersends information about the plurality of drive times calculated by thecalculation processing as the lens-side judgment data to the camerabody.

According to a tenth aspect of the present invention, in theinterchangeable lens according to the third aspect, it is preferablethat the transmitter sends at least part of the lens data stored in thestorage unit as the lens-side judgment data to the camera body.

According to an eleventh aspect of the present invention, in theinterchangeable lens according to the tenth aspect, it is preferablethat the storage unit stores the lens data including at least one of anoperation expression of the drive time and a parameter given to theoperation expression of the drive time.

According to a twelfth aspect of the present invention, in theinterchangeable lens according to any one of the first to eleventhaspects, it is preferable to further comprise: an optical systemincluding the driven member, wherein: the driven member includes any oneof a member capable of moving along an optical axis of the opticalsystem, a member capable of moving in a direction including a componentperpendicular to the optical axis, and a member capable of moving so asto change a size of an opening through which a light flux passes.

A camera body according to a thirteenth aspect of the present inventioncomprise: mount unit on which an interchangeable lens including a drivenmember and a storage medium storing lens data related to driving of thedriven member can be mounted; a receiver that receives lens-sidejudgment data, based on which whether the lens data is properly storedin the storage medium or not can be judged, from the interchangeablelens; and a judgment unit that judges whether the lens data is properlystored in the storage medium or not, based on the lens-side judgmentdata received from the receiver.

According to a fourteenth aspect of the present invention, in the camerabody according to the thirteenth aspect, it is preferable that thereceiver receives the lens-side judgment data generated based on thelens data stored in the storage medium.

According to a fifteenth aspect of the present invention, in the camerabody according to the thirteenth or fourteenth aspect, it is preferablethat the receiver receives drive time, which is required to drive thedriven member by a desired driving amount at a desired drive speed andis estimated by the interchangeable lens based on the lens data, as thelens-side judgment data from the interchangeable lens.

According to a sixteenth aspect of the present invention, in the camerabody according to the fifteenth aspect, it is preferable to furthercomprise: a storage unit that stores body-side data to be compared withthe lens-side judgment data received from the receiver, wherein: thejudgment unit performs the judgment based on the body-side data and thelens-side judgment data received from the receiver.

According to a seventeenth aspect of the present invention, in thecamera body according to the sixteenth aspect, it is preferable that thebody-side data comprises data associating information about drive timerequired to drive the driven member by a desired driving amount at adesired drive speed with the desired drive speed and the desired drivingamount.

According to an eighteenth aspect of the present invention, in thecamera body according to the seventeenth aspect, it is preferable thatthe storage unit stores a plurality of pieces of the body-side datawhich are mutually different; and the judgment unit selects one of theplurality of pieces of the body-side data stored in the storage unit andperforms the judgment by comparing the information about the drive timeincluded in the selected body-side data with the received lens-sidejudgment data.

According to a nineteenth aspect of the present invention, in the camerabody according to the fifteenth aspect, it is preferable to furthercomprise: a storage unit that stores body-side data which is partiallyidentical to the lens data stored in the storage medium; and anestimation unit that estimates drive time required to drive the drivenmember by the desired driving amount at the desired drive speed based onthe body-side data stored in the storage unit, wherein: the judgmentunit judges whether the lens data is properly stored in the storagemedium or not, by comparing the drive time estimated by the estimationunit with the lens-side judgment data received from the receiver.

According to a twentieth aspect of the present invention, in the camerabody according to the nineteenth aspect, it is preferable that thestorage unit stores the lens data including an operation expression ofthe drive time.

According to a twenty-first aspect of the present invention, in thecamera body according to the fifteenth aspect, it is preferable that thestorage unit stores an operation expression same as an operationexpression stored in the storage medium to calculate the drive time; thereceiver receives at least part of correction term data, which is storedin the storage medium and given to the operation expression to calculatethe drive time, from the storage medium; the estimation unit calculatesthe drive time based on the correction term data received from thereceiver and the operation expression; and the judgment unit performsthe judgment based on the drive time calculated by the estimation unitand the lens-side judgment data received by the receiver.

According to a twenty-second aspect of the present invention, in thecamera body according to the fifteenth aspect, it is preferable that thereceiver receives a plurality of drive times as the lens-side judgmentdata, each of the plurality of drive times corresponding to the drivetime; and the judgment unit performs the judgment based on a sizerelation between the plurality of drive times received by the receiver.

According to a twenty-third aspect of the present invention, in thecamera body according to the thirteenth or fourteenth aspect, it ispreferable that the receiver receives at least part of the lens datastored in the storage medium as the lens-side judgment data from theinterchangeable lens.

Advantageous Effect of the Invention

Driving of the driven member can be controlled with excellent precisionand certainty according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of the configuration of a camera systemaccording to a first embodiment;

FIG. 2 shows a schematic sectional view of a camera body 100 and a firstinterchangeable lens 200 a;

FIG. 3 shows a schematic sectional view of the camera body 100 and asecond interchangeable lens 200 b;

FIG. 4 shows a schematic sectional view of the camera body 100 and athird interchangeable lens 200 c;

FIG. 5 shows a flowchart illustrating initialization processing executedby a body control device 109;

FIG. 6 shows a flowchart illustrating initialization processing executedby a first lens control device 209 a;

FIG. 7 shows a flowchart illustrating photographing operation executedby the body control device 109 in a first control mode;

FIG. 8 shows a flowchart illustrating photographing operation executedby the first lens control device 209 a in the first control mode;

FIG. 9 shows a flowchart illustrating initialization processing executedby the body control device 109 according to a second embodiment;

FIG. 10 shows a flowchart illustrating initialization processingexecuted by the first lens control device 209 a according to the secondembodiment;

FIG. 11 shows a flowchart illustrating initialization processingexecuted by the body control device 109 according to a third embodiment;

FIG. 12 shows a flowchart illustrating initialization processingexecuted by the first lens control device 209 a according to the thirdembodiment;

FIG. 13 shows a flowchart illustrating initialization processingexecuted by the body control device 109 according to a fourthembodiment;

FIG. 14 shows a flowchart illustrating initialization processingexecuted by the first lens control device 209 a according to the fourthembodiment;

FIG. 15 shows the stored content of a body-side ROM according to avariation; and

FIG. 16 shows a flowchart illustrating initialization processingexecuted by the body control device 109 according to the variation.

DESCRIPTION OF EMBODIMENTS First Embodiment

A camera system according to a first embodiment, to which the presentinvention is applied, will be explained below with reference todrawings. FIG. 1 shows a perspective view of the configuration of thecamera system according to the first embodiment. The digital camerasystem illustrated in FIG. 1 is configured by including a camera body100 and a first interchangeable lens 200 a which can be mounted on thecamera body 100. Incidentally, besides the first interchangeable lens200 a, a second interchangeable lens 200 b or a third interchangeablelens 200 c can be mounted on the camera body 100. Differences betweenthese three kinds of interchangeable lenses 200 a, 200 b and 200 c willbe described later.

The camera body 100 includes a so-called bayonet-type body mount unit101. Once a lens mount unit 201 for the first interchangeable lens 200 ais set in and secured to the body mount unit 101, a plurality ofelectric contacts 202 provided on the lens mount unit 201 areelectrically connected to a plurality of electric contacts 102 providedon the body mount unit 101. The camera body 100 is also provided with arelease switch 120 capable of halfway press operation and full pressoperation.

(Description of Digital Camera System Made Up of Camera Body 100 andFirst Interchangeable Lens 200 a)

FIG. 2 is a schematic sectional view of the camera body 100 and thefirst interchangeable lens 200 a. The first interchangeable lens 200 aincludes an image forming optical system that forms a subject image onan imaging surface when receiving a light flux from a subject. Thisimage forming optical system is composed of a plurality of lenses 203,204 and 205 and an aperture 206. Of these lenses, the lens 204 is afocusing lens capable of moving in a direction of an optical axis X. Thecamera body 100 includes an image sensor 104 that captures the subjectimage formed by the image forming optical system, converts the subjectimage into an electric signal, and outputs the electric signal. Theimage sensor 104 is a solid-state image sensor such as a CCD or a CMOS.It should be noted that an infrared cut-off filter to cut off infraredlight and an optical low-pass filter to prevent aliasing noise of imagesare disposed on the imaging surface of the image sensor 104 althoughthey are not shown in FIG. 2.

A quick return mirror 103 is disposed on an optical path of the lightflux, which has transmitted through the image forming optical system, ina manner so as to shield the image sensor 104 in the camera body 100.The quick return mirror 103 is located at a position indicated with asolid line in FIG. 2 before exposure (while not photographing), so thatit reflects the subject light from the image forming optical system ontoa finder screen 107 located in an upper part of the camera body 100. Thefinder screen 107 is located at a conjugated position with the imagesensor 104 relative to the quick return mirror 103.

The subject light which has been reflected by a reflecting surface ofthe quick return mirror 103 transmits through the finder screen 107, isintroduced into a pentaprism 108 (pentagonal roof prism), and is thenoutput towards an ocular lens 110. Therefore, in a pre-exposure state, aphotographer can visually recognize the subject image through the ocularlens 110.

An area near the center of the quick return mirror 103 (including theoptical axis X of the optical system and its vicinity) constitutes ahalf mirror and part of the subject light transmits through this halfmirror part. The light flux thus transmitted is reflected by asub-mirror 105 provided on the backside of the quick return mirror 103and enters a focal point detector 106 provided in a lower part of thecamera body 100. The focal point detector 106 detects a focusing stateof the image forming optical system.

For the exposure, the quick return mirror 103 and the sub-mirror 105 aremoved to a position (retracted position) below the finder screen 107.Once the quick return mirror 103 and the sub-mirror 105 have moved tothe retracted position, the subject light which has transmitted throughthe image forming optical system is introduced into the image sensor104. Subsequently, the image sensor 104 captures the subject imageformed on the imaging surface.

The first interchangeable lens 200 a includes a first lens controldevice 209 a that controls each part of the first interchangeable lens200 a. Moreover, the camera body 100 includes a body control device 109that controls each part of the camera body 100. The first lens controldevice 209 a and the body control device 109 can perform bi-directionaldata communication by sending and receiving electric signals via theplurality of electric contacts 102, 202 provided on the respective mountunits of the camera body and the interchangeable lens.

The first interchangeable lens 200 a includes: a lens drive unit 207that drives the focusing lens 204 in a direction along the optical axisX; and an aperture drive unit 208 that drives the aperture 206 to changethe size of an opening through which the subject light passes. Each ofthe lens drive unit 207 and the aperture drive unit 208 includes anactuator (not shown in the drawing) (such as a stepping motor), and thelens drive unit 207 and the aperture drive unit 208 drive the focusinglens 204 and the aperture 206, respectively, according to a drive speed,driving amount, and drive direction given from the first lens controldevice 209 a.

The camera body 100 includes a body side aperture drive unit 111equipped with an actuator (not shown in the drawing). When aninterchangeable lens (described later) which is not equipped with adrive mechanism for the aperture 206 is mounted, the body side aperturedrive unit 111 transmits a driving force by the actuator to the aperture206 in the interchangeable lens and drives the aperture 206. Since thefirst interchangeable lens 200 a shown in FIG. 2 is equipped with theaperture drive unit 208, the body side aperture drive unit 111 doesnothing when the first interchangeable lens 200 a is mounted.

The first interchangeable lens 200 a includes a ROM 210 which is anonvolatile storage medium. The lens-side ROM 210 stores lens data(described later in detail) about driving of the aperture 206.Similarly, the camera body 100 includes a body-side ROM 112 which is anonvolatile storage medium. Body-side judgment data (body-side data)(described later in detail) based on which whether the lens data isproperly stored in the lens-side ROM 210 described later is judged isstored in the body-side ROM 112 in advance.

The first lens control device 209 a sends to the body control device 109lens-side judgment data, which enables the camera body 100 (the bodycontrol device 109) to judge whether the lens data is properly stored inthe lens-side ROM 210 or not, based on the lens data (described later indetail) stored in the lens-side ROM 210. The body control device 109judges whether the lens data is properly stored in the lens-side ROM 210or not by comparing the body-side judgment data (or body-side data)stored in the body-side ROM 112 with the above-described receivedlens-side judgment data. This judgment will be explained later indetail.

(Description of Driving of Aperture)

Before having the interchangeable lens 200 start controlling driving ofthe aperture, the body control device 109 firstly identifies what kindof interchangeable lens is mounted on the body mount unit 101 (the typeof the interchangeable lens), by means of initial communication with theinterchangeable lens 200 via the aforementioned electric contacts 102and 202. The body control device 109 identifies whether it is the firstinterchangeable lens 200 a, the second interchangeable lens 200 b, orthe third interchangeable lens 200 c, based on the content of the lensdata acquired from the interchangeable lens 200 through the initialcommunication (or based on, for example, whether the lens data has beenacquired or not).

This first embodiment will be described below about a case where (thebody control device 109 determines that) the first interchangeable lens200 a is mounted on the body mount unit 101.

When it is necessary to change an opening diameter of the aperture 206,for example, for exposure, the body control device 109 sends an aperturedrive command to the first lens control device 209 a through datacommunication via the plurality of electric contacts 102 and 202. Afterreceiving the aperture drive command from the body control device 109,the first lens control device 209 a controls the aperture drive unit 208in accordance with parameters of the aperture drive command and has theaperture drive unit 208 drive the aperture 206.

The aperture drive command includes the parameters which represent thedriving amount, drive direction, and drive speed of the aperture 206.For example, assuming that the opening diameter of the current aperture206 is of a size corresponding to F2 and this needs to be changed to asize corresponding to F4, the body control device 109 sends the aperturedrive command to the first lens control device 209 a in order to set thedriving amount to an amount corresponding to “2 steps,” the drivedirection to a “constricting direction,” and the drive speed to a“highest speed.” When receiving the aperture drive command to set thedrive speed to the “highest speed” from the body control device 109, thelens control device 209 a for the interchangeable lens 200 a controlsand drives the aperture 206 to a target aperture position (by thedriving amount) at the maximum aperture drive speed which theinterchangeable lens 200 a (the aperture drive unit 208) can operate.

Incidentally, if the driving amount of the aperture 206 is defined asthe “number of aperture steps from the maximum aperture,” it isunnecessary to include the parameter, which represents the “drivedirection,” independently from the above-mentioned “driving amount” inthe “aperture drive command”.

The body control device 109 usually designates the “highest speed” asthe drive speed of the aperture 206. However, the body control device109 sends the aperture drive command, which designates a value otherthan the “highest speed” as the drive speed, to the first lens controldevice 209 a in any of the following circumstances: (1) if powerconsumption of the first interchangeable lens 200 a needs to besuppressed; (2) if operation sound of the first interchangeable lens 200a needs to be reduced; or (3) if the aperture 206 is to be driven whilephotographing a moving image.

The case (1) where “power consumption of the first interchangeable lens200 a needs to be suppressed” means, for example, when remaining batterypower is low or when a user designates power-saving operation. The case(2) where the “operation sound of the first interchangeable lens 200 aneeds to be reduced” means, for example, when the sound is recorded atthe same time as photographing or when the user designates silentoperation. The case (3) where the “aperture 206 is to be driven whilephotographing a moving image” means, for example, when the userdesignates to photograph such a moving image.

The body control device 109 sends an aperture drive time estimatecommand to the first lens control device 209 a before sending theabove-described aperture drive command.

Now, the “aperture drive time estimate command” which is output from thecamera body 100 to the interchangeable lens 200 will be explained. Theaperture drive time estimate command is a command for instructing, theinterchangeable lens 200 (the first lens control device 209 a) toestimate a drive time required when the aperture drive unit 208 at theinterchangeable lens 200 is controlled to drive the aperture 206 by theaperture driving amount (the number of steps) designated by the camerabody 100 at the aperture drive speed also designated by the camera body100 (for example, by means of forecasting calculation) and to output (orsend) the result of the estimate (for example, the forecastingcalculation) to the camera body 100.

After receiving the estimated result (estimated drive time of theaperture), the camera body (the body control device 109) uses theestimated drive time for timing control related to photographingoperation, for example, timing control related to the exposureprocessing. Examples of timing control of the exposure processinginclude timing control of opening and closing of a shutter whenphotographing still images and timing control of photographicsensitivity to change the photographic sensitivity according tomovements of the aperture so that changes in the exposure may not occur(or a constant exposure amount may be maintained) even if an aperturevalue (aperture opening size) is changed when photographing a movingimage.

After receiving the aperture drive time estimate command from the bodycontrol device 109, the first lens control device 209 a estimates (orcalculates) time required to drive the aperture 206 based on the contentof the aperture drive time estimate command (at least including anaperture driving amount a and an aperture drive speed v). Then, thefirst lens control device 209 a sends (or returns) the estimated (orcalculated) drive time to the body control device 109.

The first lens control device 209 a estimates the drive time based onthe lens data stored in the lens-side ROM 210. Now, the lens data in thelens-side ROM 210 will be explained. The lens-side ROM 210 includes anoperation expression to calculate the estimated drive time T from theaperture driving amount a and the aperture drive speed v mentionedabove, as the lens data. An example of that operation expression isindicated as the following expression (1):

T=a/v+α  (1)

In the above expression, a represents a correction term for the aperturedrive time and is decided in consideration of, for example, delay timefrom the start of drive control of the aperture 206 until actual startof driving of the aperture 206 and time it takes from when the aperture206 is driven by a target driving amount until the aperture 206 becomesstatic and stable. A different value is stored as this correction term αfor each interchangeable lens. Furthermore, a different value may bestored as the correction term α according to lens setting conditions(for example, according to a focal length in a case of zoom lens)depending on the type of the interchangeable lens. The lens data of thelens-side ROM 210 also includes the value of this correction term α andthat value is decided when designing the first interchangeable lens 200a. For example, if the aperture driving amount a is “2 steps,” theaperture drive speed v is “10 steps/second,” and the correction term αis “0.1 seconds,” the first lens control device 209 a calculates theestimated drive time T as 0.3 seconds according to the aforementionedexpression (1). Incidentally, a plurality of correction terms a may bestored (or provided) according to the drive speed and the driving amount(or the number of steps).

The body control device 109 controls, for example, shutter releasetiming for still image photographing based on the estimated drive time Testimated as explained above.

(Description of Digital Camera System Made Up of Camera Body 100 andSecond Interchangeable Lens 200 b)

FIG. 3 is a schematic sectional view of the camera body 100 and thesecond interchangeable lens 200 b. Differences between the secondinterchangeable lens 200 b and the first interchangeable lens 200 a willbe explained below.

The second interchangeable lens 200 b includes a second lens controldevice 209 b instead of the first lens control device 209 a.

The body control device 109 firstly performs initial communication withthe second lens control device 209 b via the aforementioned electriccontacts 102 and 202 and identifies, based on the communication results,that the second interchangeable lens 200 b is mounted on the body mountunit 101.

The second lens control device 209 b, unlike the first lens controldevice 209 a, does not support any designation of the drive speed of theaperture 206. Therefore, the body control device 109 sends an aperturedrive command whose content is different from that of the aforementionedaperture drive command (which is sent to the first lens control device209 a), that is, the aperture drive command which does not include theaperture drive speed, to the second lens control device 209 b.

After receiving the aperture drive command sent from the body controldevice 109, the second lens control device 209 b, like the first lenscontrol device 209 a, controls the aperture drive unit 208 and has theaperture drive unit 208 drive the aperture 206 in accordance with thecontent of the aperture drive command. However, since the aperture drivecommand does not include any designation of the aperture drive speed,the aperture 206 is always driven at a specified speed (for example, thehighest possible speed of the second interchangeable lens 200 b) whenthe second interchangeable lens 200 b is mounted on the camera body 100.

Furthermore, the second lens control device 209 b does not performestimation (or calculation) of the drive time of the aperture 206 whichwas performed in the aforementioned first interchangeable lens 200 a.Moreover, the second interchangeable lens 200 b does not include thelens-side ROM 210 which stores the aforementioned lens data.

Meanwhile, the aperture drive commands are not limited to the exampleexplained above (the example in which the first interchangeable lens 200a and the second interchangeable lens 200 b use mutually differentcommands) and, for example, the first interchangeable lens 200 a and thesecond interchangeable lens 200 b can share an aperture drive commandoutput by the body control device 109. If such a shared aperture drivecommand is to be used, the second lens control device 209 b may beconfigured so that it refers to the parameters representing the drivingamount and the drive direction of the aperture 206 and included in theaperture drive command, but does not refer to the parameter representingthe drive speed of the aperture 206. As the second lens control device209 b is configured in this way, when the second interchangeable lens200 b is mounted on the camera body 100 in the same manner, the aperture206 will be always driven at a specified speed (for example, at thehighest speed) as described above.

(Description of Digital Camera System Made Up of Camera Body 100 andThird Interchangeable Lens 200 c)

FIG. 4 is a schematic sectional view of the camera body 100 and thethird interchangeable lens 200 c. Differences between the thirdinterchangeable lens 200 c and the first interchangeable lens 200 a willbe explained below.

The third interchangeable lens 200 c includes a third lens controldevice 209 c instead of the first lens control device 209 a.

The body control device 109 firstly performs initial communication withthe third lens control device 209 c via the aforementioned electriccontacts 102 and 202 and identifies, based on the communication results,that the third interchangeable lens 200 c is mounted on the body mountunit 101.

The third interchangeable lens 200 c does not include the aperture driveunit 208 and the third lens control device 209 c thereby does notsupport any operation corresponding to the aperture drive command.Specifically speaking, the third interchangeable lens 200 c cannot drivethe aperture 206 by itself. Instead, an aperture operating lever (notshown in the drawing) which is connected to the aperture 206 is providednear the lens mount unit 201 for the third interchangeable lens 200 c.This aperture operating lever is a lever capable of moving in aspecified direction. The position of the aperture operating levercorresponds to the size of the opening diameter of the aperture 206.When the aperture operating lever is moved, the opening diameter of theaperture 206 changes accordingly. Specifically speaking, when theopening diameter of the aperture 206 is to be set to a certain size, itis only necessary to move the aperture operating lever to a positioncorresponding to that opening diameter.

When the third interchangeable lens 200 c is mounted on the camera body100, the aperture operating lever engages with a drive member (not shownin the drawing) included in the body side aperture drive unit 111. Thebody side aperture drive unit 111 is equipped with an actuator (notshown in the drawing) that drives this drive member. When the body sideaperture drive unit 111 drives the drive member, the aperture operatinglever engaged with the drive member moves and the opening diameter ofthe aperture 206 changes. Specifically speaking, the body side aperturedrive unit 111 drives the aperture 206 included in the thirdinterchangeable lens 200 c. When the third interchangeable lens 200 c ismounted, the body control device 109 controls the body side aperturedrive unit 111 to drive the aforementioned drive member instead ofsending the aperture drive command to the third lens control device 209c, thereby changing the opening diameter of the aperture 206 to adesired size.

Furthermore, the third lens control device 209 c does not supportestimation (or calculation) of the drive time of the aperture 206.Moreover, the third interchangeable lens 200 c does not include thelens-side ROM 210 which stores the aforementioned lens data.

(Description of Initialization Processing by Digital Camera System MadeUp of Camera Body 100 and Interchangeable Lens 200)

Next, initialization processing executed by the body control device 109and the control device 209 of each lens (particularly the first lenscontrol device 209 a) will be explained. The body control device 109executes the initialization processing at specified timing, for example,when the interchangeable lens is mounted on the camera body 100 in apower-on state or when the interchangeable lens is mounted on the camerabody 100 in a power-off state and then the camera body 100 enters thepower-on state. The body control device 109 sets any one of the first tofourth control modes to the camera body 100 during the initializationprocessing explained below. The details of each control mode will beexplained later. Incidentally, the first lens control device 209 a, thesecond lens control device 209 b, and the third lens control device 209c will be collectively referred to as the “lens control device” in thefollowing explanation.

FIG. 5 is a flowchart illustrating the initialization processingexecuted by the body control device 109. Firstly, communications areestablished between the body control device 109 and the lens controldevice 209; and then in first Step S100, the body control device 109sends a “lens function data request command” to the lens control device.In Step S110, the body control device 109 receives “lens function data”which is sent from the lens control device as a response to theabove-mentioned command. The lens function data is data used to identifyfunctions of the interchangeable lens and contains information about,for example, whether the aperture drive unit 208 exists or not, whetherthe drive speed of the aperture 206 can be designated or not, thehighest possible drive speed of the aperture 206 (the aforementionedhighest speed of the aperture), and whether a zooming mechanism existsor not.

In Step S120, whether the interchangeable lens mounted on the body mountunit 101 is the third interchangeable lens 200 c or not is judged basedon the content of the lens function data received in Step S110. Forexample, if it is recognized based on the lens function data that theaperture drive unit 208 does not exist, it is determined that the thirdinterchangeable lens 200 c is mounted. If it is determined that thethird interchangeable lens 200 c is mounted, the processing proceeds toStep S121 and the control mode of the camera body 100 is set to thethird control mode. If the third control mode is set, the body controldevice 109 controls driving of the aperture 206 by using the body sideaperture drive unit 111 and does not send the aperture drive command tothe lens control device.

On the other hand, if it is determined in Step S120 that aninterchangeable lens other than the third interchangeable lens 200 c ismounted, the processing proceeds to Step S130. In Step S130, whether theinterchangeable lens mounted on the body mount unit 101 is the secondinterchangeable lens 200 b or not is judged based on the content of thelens function data received in Step S110. For example, if it isrecognized based on the lens function data that the drive speed of theaperture 206 cannot be designated, it is determined that the secondinterchangeable lens 200 b is mounted. If it is determined that thesecond interchangeable lens 200 b is mounted, the processing proceeds toStep S131 and the control mode of the camera body 100 is set to thesecond control mode. If the second control mode is set, the body controldevice 109 controls driving of the aperture 206 by sending the aperturedrive command to the lens control device, but the sent aperture drivecommand does not include the drive speed of the aperture 206.

On the other hand, if it is determined in Step S130 that aninterchangeable lens other than the second interchangeable lens 200 b ismounted, the processing proceeds to Step S140. Incidentally, in thisembodiment, the processing proceeds to Step S140 when an interchangeablelens which is neither the third interchangeable lens 200 c nor thesecond interchangeable lens 200 b is mounted, that is, when the firstinterchangeable lens 200 a is mounted.

In Step S140, the body control device 109 sends a “judgment data requestcommand” to the first lens control device 209 a. In Step S150, the bodycontrol device 109 receives “lens-side judgment data” sent from thefirst lens control device 209 a as a response to the above-mentionedcommand. The lens-side judgment data used for judgment on the camerabody in this embodiment is the lens data itself stored in the lens-sideROM 210. The lens data contains, as described earlier, the operationexpression (1) “T=a/v+α” to calculate the estimated drive time T fromthe aperture driving amount (the number of steps to be driven) a and theaperture drive speed v, and the correction term α of the aperture drivetime used for the above operation expression. Therefore, the lenscontrol device 209 a sends the operation expression (1) “T=a/v+α” andthe correction term α, which are generated based on the lens data, asthe lens-side judgment data to the camera body. Incidentally, thelens-side ROM 210 stores the correction term α as numerical value dataand stores the operation expression (1) as character-string data and thelens control device 209 a sends the numerical value data and thecharacter-string data to the camera body.

In Step S160, the body control device 109 compares the body-sidejudgment data stored in the body-side ROM 112 with the lens-sidejudgment data received in Step S150 and judges whether the contents ofthese two pieces of data are identical or not. The content of thebody-side judgment data in this embodiment is the lens-side judgmentdata itself which is stored in the body-side ROM 112 in advance (thatis, the aforementioned operation expression (1) and the correction termα). Specifically speaking, in this embodiment, each of the body-side ROM112 and the lens-side ROM 210 stores the judgment data of the samecontent (the operation expression (1) “T=a/v+α” and the correction termα) in advance; and in Step S160, the body control device 109 judgeswhether the contents of these two pieces of lens data are identical ornot.

If the content of the body-side judgment data and the content of thelens-side judgment data are judged to be identical in Step S160, theprocessing proceeds to Step S161 and the body control device 109 setsthe control mode of the camera body 100 to the first control mode. Ifthe first control mode is set, the body control device 109 controlsdriving of the aperture 206 by sending the aperture drive commandincluding the drive speed of the aperture 206 to the lens controldevice. Furthermore, if the first control mode is set, the body controldevice 109 acquires the estimated drive time by sending an aperturedrive time estimate command to the lens control device 209 beforedriving the aperture 206, and then controls driving of the aperture 206by using this estimated drive time.

On the other hand, if the content of the body-side judgment data and thecontent of the lens-side judgment data are judged to be not identical inStep S160, the processing proceeds to Step S162. In this case, the bodycontrol device 109 judges that the lens data stored in the ROM 210 inthe first interchangeable lens 200 a is damaged due to strong electricimpacts such as static electricity; and the body control device 109 thensets the fourth control mode, by which driving of the aperture 206 isrestricted, to the camera body 100. In the fourth control mode, the bodycontrol device 109 does not send the aperture drive command to the firstlens control device 209 a and performs, for example, photographingoperation while keeping an opening diameter of the aperture 206 fixed.Furthermore, the body control device 109 displays a message (so-calledwarning display) indicating that there is inconsistency in the storedcontent of the ROM 210 (for example, there is a failure on the lensside), on a display device (not shown in the drawing) (such as a liquidcrystal display) so as to notify the user that control of the aperture206 is limited.

Incidentally, this embodiment has described the content of theaforementioned “fourth control mode” as displaying the above-mentionedmessage and limiting control of the aperture 206. However, the contentset in the fourth control mode is not limited to that described above.For example, the content of the fourth control mode may be limited toonly the aforementioned alarm display. Alternatively, any strongerlimitation may be applied by, for example, limiting power supply fromthe camera body to an accessory (for example, by prohibiting the supplyof power which should be supplied to the aperture drive system).Furthermore, any stronger limitation may be applied by, for example,prohibiting the photographing operation on the camera body side.

Furthermore, the alarm display method is not limited to the display ofthe aforementioned message and any display form may be used as long as awarning about the occurrence of a failure on the lens can be reported tothe user. For example, a flashing or lighting alarm display using, forexample, LEDs may be employed. Alternatively, a simple message display(such as “Aperture NG”) indicating that the aperture control is limited,or an icon display indicating the aperture NG may be brought up on, forexample, a liquid crystal display.

FIG. 6 is a flowchart illustrating lens initialization processingexecuted by the first lens control device 209 a. Firstly in Step S200,the first lens control device 209 a receives the “lens function datarequest command” from the body control device 109 (corresponding to StepS100 in FIG. 5). In Step S210, the first lens control device 209 a sendsthe “lens function data” to the body control device 109 (correspondingto Step S110 in FIG. 5). In Step S220, the first lens control device 209a receives the “judgment data request command” from the body controldevice 109 (corresponding to Step S140 in FIG. 5). In Step S230, thefirst lens control device 209 a reads the lens data from the ROM 210 andsends the read lens data as the “lens-side judgment data” to the bodycontrol device 109 (corresponding to Step S150 in FIG. 5).

(Description of Photographing Operation)

FIG. 7 is a flowchart illustrating the photographing operation executedby the body control device 109 in the first control mode. Firstly inStep S300, the body control device 109 accepts halfway press operationof the release switch 120 by the user. In Step S310, the body controldevice 109 executes well-known automatic exposure (AE) control andautomatic focus adjustment (AF) control. The body control device 109calculates the opening diameter of the aperture 206 (or an aperturevalue), exposure time of the image sensor 104 and the like at the timeof exposure by performing this AE control.

Subsequently in Step S320, the body control device 109 accepts fullpress operation of the release switch 120 by the user. The body controldevice 109 starts exposure control in response to this full pressoperation.

In Step S330, the body control device 109 sends the aperture drive timeestimation command to the first lens control device 209 a. This commandincludes a parameter corresponding to the opening diameter (or theaperture value) calculated in Step S310. Specifically speaking, theaperture drive time estimation command which is sent here is a commandto have the first lens control device 209 a estimate time required todrive the aperture 206 from the current opening diameter to the openingdiameter calculated in Step S310.

In Step S340, the body control device 109 receives the estimated drivetime of the aperture 206 from the first lens control device 209 a. InStep S350, the body control device 109 sends the aperture drive commandto the first lens control device 209 a to drive the aperture 206 to theopening diameter (or the aperture value) calculated in Step S310. Thiscommand includes a parameter corresponding to the opening diameter (orthe aperture value) calculated in Step S310.

In Step S360, the body control device 109 judges whether the estimateddrive time of the aperture 206 as received in Step S340 is more than apredetermined threshold value or not. In this embodiment, this thresholdvalue is defined as a value of a release time lag in the camera body 100(for example, time required to drive the quick return mirror 103 to itsretracted position). Specifically speaking, in Step S360, whether thetime required for photographing preparation of the aperture 206 is morethan the time required for photographing preparation on the camera body100 side or not is judged.

If it is judged in Step S360 that the estimated drive time is more thanthe predetermined threshold value, the processing proceeds to Step S370.In Step S370, the body control device 109 waits as long as necessary forthe completion of driving of the aperture 206; and then the processingproceeds to Step S380. The waiting time here is time obtained bysubtracting the release time lag on the camera body 100 side from theestimated drive time of the aperture 206. On the other hand, if theestimated drive time is equal to or less than the predeterminedthreshold value in Step S360, driving of the aperture 206 must have beencompleted when the photographing preparation on the camera body 100 sideis completed, so that the processing proceeds to Step S380 withoutproviding the waiting time as in Step S370. In Step S380, thephotographing operation is executed. Specifically speaking, the imagesensor 104 is exposed to light and the body control device 109 createsphotographed image data based on light reception output of the imagesensor 104.

FIG. 8 is a flowchart illustrating photographing operation executed bythe first lens control device 209 a in the first control mode. Firstlyin Step S400, the first lens control device 209 a receives the aperturedrive time estimation command from the body control device 109(corresponding to Step S330 in FIG. 7). Then in Step S410, the firstlens control device 209 a estimates the drive time of the aperture 206(or calculates the estimated drive time) based on the parametersincluded in the received aperture drive time estimation command (theaperture driving amount a and the aperture drive speed v) and the lensdata stored in the lens-side ROM 210 (the aforementioned operationexpression (1) and the correction term α). In Step S420, the first lenscontrol device 209 a sends the estimated drive time calculated in StepS410 to the body control device 109 (corresponding to Step S340 in FIG.7).

In Step S430, the first lens control device 209 a receives the aperturedrive command from the body control device 109 (corresponding to StepS350 in FIG. 7). Then in Step S440, the first lens control device 209 acontrols the aperture drive unit 208 based on the parameters included inthe received aperture drive command so as to drive the aperture 206 bythe designated driving amount in the designated drive direction and atthe designated drive speed.

The camera system according to the aforementioned first embodiment canachieve the following operations and effects. (1) The firstinterchangeable lens 200 a includes: the optical system including theaperture 206 which is the driven member; the aperture drive unit 208that drives the aperture 206; and the lens-side ROM 210 that stores thelens data about driving of the aperture 206 by the aperture drive unit208. The first lens control device 209 a sends to the camera body 100the lens-side judgment data, which is configured based on the lens datastored in the lens-side ROM 210 and based on which whether the lens datais properly stored in the lens-side ROM 210 or not can be judged. As aresult, whether the lens data is true or false can be judged on thecamera body side by using the lens data which is used for actualphotographing operation (or aperture control operation). If it isdetermined as “true” for this judgment, the data retained in thelens-side ROM 210 can be used by considering that such data is highlysafe, that is, the lens data stored in the lens-side ROM 210 is properlystored. Accordingly, it can be considered that the estimated drive timeof the aperture 206 will be calculated properly during the subsequentphotographing operation.

(2) The body control device 109 receives the lens-side judgment data,which is configured based on the lens data stored in the lens-side ROM210 and based on which whether the lens data is properly stored in thelens-side ROM 210 or not can be judged on the camera body 100, from thefirst interchangeable lens 200 a, and judges whether the lens data isproperly stored in the lens-side ROM 210 or not, based on the lens-sidejudgment data. As a result, whether the lens data about the aperturedrive control is true or false can be judged before the actualphotographing operation (or aperture control operation), so that it ispossible to prevent failed photographing based on erroneous lens-sidedata.

(3) The first lens control device 209 a estimates the drive timerequired for the aperture drive unit 208 to drive the aperture 206 by aspecified amount at a specified speed based on the lens data stored inthe ROM 210. As a result, it is possible for the camera body 100 tofacilitate timewise collaboration between aperture driving on theinterchangeable lens 200 side and shutter driving on the camera bodyside, thereby shortening the release time lag.

(4) The first lens control device 209 a sends the lens data stored inthe lens-side ROM 210 as the lens-side judgment data to the camera body100. Also, the body control device 109 receives the lens data stored inthe lens-side ROM 210 as the lens-side judgment data from the firstinterchangeable lens 200 a. As a result, whether the lens-side data (orthe lens data) which is to be used for the actual photographingoperation (or the aperture control operation) is true or false is judgedby using the lens-side data (or the lens data) itself. If it isdetermined as a result of this judgment that the lens-side data (or thelens data) is “true,” it can be considered that the lens data isproperly stored and that the estimated drive time of the aperture 206will be calculated properly during the subsequent photographingoperation.

Second Embodiment

The configuration of a camera system according to a second embodiment ofthe present invention is the same as that of the first embodiment,except for some part of it. The difference between the second embodimentand the first embodiment will be explained below. Incidentally, in thefollowing explanation, the same reference numerals as those in the firstembodiment are assigned to the same elements as those in the firstembodiment and an explanation about them has been omitted.

The camera system according to the second embodiment is equipped with ameans capable of calculating (or generating) simplified estimated drivetime T′ relating to the estimated drive time T of the aforementionedaperture 206 by a “simpler method” (for example, by simplifiedcalculation) than the aforementioned first embodiment separately fromthe means of estimating the estimated drive time T; and the estimateddrive time (or a simplified calculated value) of the aperture ascalculated by the simple method is defined as the lens-side judgmentdata.

Now, the above-mentioned “simple method” will be explained. In the firstembodiment, the lens-side ROM 210 stores, as the lens data, theoperation expression (1) “T=a/v+α” (the aperture driving amount a, theaperture drive speed v, the estimated drive time T, and the correctionterm α) and the correction term α, and the estimated drive time T iscalculated by using this operation expression (1). On the other hand,the lens-side ROM 210 according to this second embodiment stores,besides the combination of the above-mentioned operation expression (1)and the correction term α, simplified operation expression (2) “T′=a/v”obtained by excluding the correction term α from the above operationexpression (1). The “simple method” according to the second embodimentis to calculate (or generate) the “simplified estimated drive time T′”by using this simplified operation expression (2). As is apparent fromthe operation expression (2), the “simplified estimated drive time T′”is time calculated by using only the aperture driving amount a and theaperture drive speed v.

The body control device 109 sends to the first lens control device 209 aa “simplified aperture drive time estimation command” that includesdesired parameters (a desired aperture driving amount (the number ofsteps) a and a desired aperture drive speed v) and requests the“simplified estimated drive time T′” from the interchangeable lens 200a, instead of the aforementioned judgment data request command in thefirst embodiment.

On the other hand, the body control device 109 stores the simpleoperation expression “T′=a/v” in advance, which has the same content asthat of the above-mentioned simple operation expression (2), as thebody-side data in the body-side ROM 112. Specifically speaking, thesimple operation expression “T′=a/v” is an operation expression which isstored commonly in both the body-side ROM 112 and the lens-side ROM 210(the above-described simple operation expression (2) will be hereinaftersometimes referred to as the “common operation expression”).

After sending the “simplified aperture drive time estimation command” tothe first lens control device 209 a, the body control device 109independently estimates the aperture drive time based on theabove-described common operation expression (the body-side data) storedin the body-side ROM 112 and the above-described desired parameters (theaperture driving amount a and the aperture drive speed v) sent to theinterchangeable lens 200 a.

Specifically speaking, the body control device 109 applies theabove-mentioned desired parameters (the aperture driving amount a andthe aperture drive speed v) to the common operation expression includedin the body-side data and calculates the simplified estimated drive timeT′. Then, the body control device 109 compares the simplified estimateddrive time T′ received from the first lens control device 209 a with thesimplified estimated drive time T′ calculated by itself. If these valuesare identical, the body control device 109 judges that the lens data(not only the operation expression (2), but also the operationexpression (1) and the correction term α) is properly stored in thelens-side ROM 210.

FIG. 9 is a flowchart illustrating initialization processing executed bythe body control device 109 according to the second embodiment.Incidentally, the processing from Step S100 to S130 is the same as thatof the lens initialization processing (FIG. 5) according to the firstembodiment, so its explanation has been omitted.

If the body control device 109 determines in Step S130 that the firstinterchangeable lens 200 a is mounted, the processing proceeds to StepS500. In Step S500, the body control device 109 sends a simplifiedaperture drive time estimation command including desired parameters (theaperture driving amount a and the aperture drive speed v) to the firstlens control device 209 a. The parameters which are set here may befixed values (specified parameters, that is, a combination of aspecified aperture driving amount a and a specified aperture drive speedv) or different random values which vary every time the initializationprocessing is executed (which may be a combination of both random valuesof the aperture driving amount a and the aperture drive speed v or acombination of these values, only either one of which is a randomvalue). In subsequent Step S510, the body control device 109 receivesthe simplified estimated drive time T′ from the first lens controldevice 209 a.

In Step S520, the body control device 109 estimates the drive time ofthe aperture 206 in a simple manner based on the body-side data (thecommon operation expression) stored in the body-side ROM 112 and theparameters for the aperture drive time estimation command (the aperturedriving amount a and the aperture drive speed v) sent in Step S500.Then, in Step S530, the body control device 109 judges whether thesimplified estimated drive time T′ received in Step S510 and thesimplified estimated drive time T′ calculated in Step S520 are identicalor not. If these two values are identical, the processing proceeds toStep S161 and the body control device 109 sets the control mode of thecamera body 100 to the first control mode.

On the other hand, if the simplified estimated drive time T′ calculatedon the body side and the simplified estimated drive time T′ calculatedon the lens side are judged to be not identical in Step S530, theprocessing proceeds to Step S162. In this case, the body control device109 judges that the aforementioned lens data (not only the operationexpression (2), but also the operation expression (1) and the correctionterm α) stored in the lens-side ROM 210 in the first interchangeablelens 200 a is damaged due to strong electric impacts such as staticelectricity; and the body control device 109 sets the fourth controlmode, by which driving of the aperture 206 is restricted, to the camerabody 100.

FIG. 10 is a flowchart illustrating initialization processing executedby the first lens control device 209 a according to the secondembodiment. Incidentally, the processing in Steps S200 and S210 is thesame as that of the lens initialization processing (FIG. 6) according tothe first embodiment, so its explanation has been omitted.

In Step S600, the first lens control device 209 a receives the“simplified aperture drive time estimation command” from the bodycontrol device 109 (corresponding to Step S500 in FIG. 9). In Step S610in the same manner as in Step S410 in FIG. 8, the first lens controldevice 209 a estimates the drive time of the aperture in a simplifiedmanner (or calculates the simplified estimated drive time T′) based onthe parameters included in the received simplified aperture drive timeestimation command (the aperture driving amount a and the aperture drivespeed v) and the lens data (or the common operation expression) storedin the lens-side ROM 210. In Step S620, the first lens control device209 a sends the simplified estimated drive time T′ calculated in StepS610 to the body control device 109 (corresponding to Step S510 in FIG.9).

The camera system according to the aforementioned second embodiment canachieve the following operations and effects. (1) The first lens controldevice 209 a sends the simplified estimated drive time T′ of theaperture 206 as the lens-side judgment data to the camera body 100.Furthermore, the body control device 109 receives the result T′ of thesimplified calculation of the drive time required to drive the aperture206 by an arbitrary amount (the number of steps) at an arbitrary speed,which was calculated by the first lens control device 209 a based on thelens data (or the common operation expression), as the lens-sidejudgment data from the first interchangeable lens 200 a. The lens data(or the common operation expression) same as part of the lens data (orthe common operation expression) stored in the lens-side ROM 210 in thefirst interchangeable lens 200 a is stored in the body-side ROM 112 inthe camera body 100. The body control device 109 estimates, in asimplified manner, the drive time required to drive the aperture 206 bythe arbitrary amount (the number of steps) at the arbitrary speed basedon the lens data (or the common operation expression) stored in thebody-side ROM 112; and then compares the simplified estimated drive timeT′ with the lens-side judgment data (the simplified estimated drive timeT′ calculated on the lens side) received from the first interchangeablelens 200 a. In this manner, the lens-side judgment data stored in thelens-side ROM 210 can be handled as highly safe data (the lens-sidejudgment data stored in the lens-side ROM 210 can be considered as beingproperly stored). Consequently, the lens-side ROM itself can be handledas being highly safe. Specifically speaking, all pieces of the lens datain the lens-side ROM 210 (all three of the common operation expression,the operation expression (1), and the correction term α) can beconsidered as being highly safe (by considering that they are properlystored). As a result, the safety or stability of the lens data can beconfirmed with only the calculation result of the simplified estimateddrive time T′ and, therefore, it is possible to reduce the size of thelens-side judgment data and reduce communication loads. It is alsopossible to judge not only whether the lens data is properly stored ornot, but also whether or not the simplified estimated drive time T′ canbe properly calculated by using the lens data (the operation expression(2) which is part of the operation expression (1)), that is, to performpartial judgment of the operation expression (1).

Third Embodiment

The configuration of a camera system according to a third embodiment ofthe present invention is the same as that of the first embodiment,except for some part of it. The difference between the third embodimentand the first embodiment will be explained below. Incidentally, in thefollowing explanation, the same reference numerals as those in the firstembodiment are assigned to the same elements as those in the firstembodiment and an explanation about them has been omitted.

With the camera system according to the third embodiment, the body-sidedata as explained in each of the aforementioned embodiments is notstored in the body-side ROM 112 of the camera body 100. The body controldevice 109 sends two aperture drive time estimation commands whoseparameters are different (at least either one of the values of theaperture driving amount a and the aperture drive speed v is different)to the first lens control device 209 a. Then, the body control device109 judges whether the lens data is properly stored in the lens-side ROM210 by judging whether the size relation between two estimated drivetimes obtained by the respective commands is as expected or not.

For example, let us assume that the first aperture drive time estimationcommand (hereinafter sometimes referred to as the “aperture drive timeestimation command A”) is a command to estimate the drive time whendriving the aperture 206 by a 2-step amount (the aperture driving amounta=2 steps) in a specified direction at specified aperture drive speed;and the second aperture drive time estimation command (hereinaftersometimes referred to as the “aperture drive time estimation command B”)is a command to estimate the drive time when driving the aperture 206 bya 4-step amount (the aperture driving amount a=4 steps) in the samedirection and at the same aperture drive speed as those of the firstaperture drive time estimation command. In this case, the estimateddrive time (time calculated by using v=the specified speed, a=2 steps,the aforementioned operation expression (1), and the correction term α)sent from the first lens control device 209 a as a response to the firstaperture drive time estimation command should be smaller than theestimated drive time (time calculated by using v=the specified speed,a=4 steps, the aforementioned operation expression (1), and thecorrection term α) sent as a response to the second aperture drive timeestimation command because the aperture driving amount (2 steps) for theaperture drive time estimation command A is less than the aperturedriving amount (4 steps) for the aperture drive time estimation commandB. As a matter of course, the body control device 109 expects, among theestimated drive times sent from the first lens control device 209 a,that the estimated drive time in response to the aperture drive timeestimation command A is smaller (or shorter) then the estimated drivetime in response to the aperture drive time estimation command B. So,the body control device 109 judges whether the first estimated drivetime is smaller than the second estimated drive time or not, therebyexamining whether the first lens control device 209 a has estimated thedrive time of the aperture 206 successfully and properly, that is,whether the lens data is properly stored in the lens-side ROM 210 ornot. In this third embodiment, when the first estimated drive time issmaller than the second estimated drive time, it is determined that thefirst lens control device 209 a has estimated the drive time of theaperture 206 successfully and properly.

FIG. 11 is a flowchart illustrating lens initialization processingexecuted by the body control device 109 according to the thirdembodiment. Incidentally, the processing from Step S100 to S130 is thesame as that of the lens initialization processing (FIG. 5) according tothe first embodiment, so its explanation has been omitted.

If the body control device 109 determines in Step S130 that the firstinterchangeable lens 200 a is mounted, the processing proceeds to StepS700. In Step S700, the body control device 109 sends an aperture drivetime estimation command including specified parameters (hereinafterreferred to as the aperture drive time estimation command A) to thefirst lens control device 209 a. The parameters which are set here maybe fixed values or different random values every time the initializationprocessing is executed. In subsequent Step S710, the body control device109 receives the estimated drive time (hereinafter referred to as theestimated drive time A) from the first lens control device 209 a.

In Step S720, the body control device 109 sends an aperture drive timeestimation command including different parameters from those sent inStep S700 (hereinafter referred to as the aperture drive time estimationcommand B). It is assumed that the parameters included in the aperturedrive time estimation command B are parameters which will ensure largerdrive time as the estimated result than that resulted from theparameters included in the aperture drive time estimation command A. Forexample, the same drive direction and drive speed may be used and thedriving amount of the aperture drive time estimation command B may belarger. Alternatively, the same driving amount and drive direction maybe used and a lower drive speed may be employed for the drive timeestimation command B. In subsequent Step S730, the body control device109 receives the estimated drive time (hereinafter referred to as theestimated drive time B) from the first lens control device 209 a.

In Step S740, the body control device 109 judges whether the estimateddrive time A received in Step S710 is smaller than the estimated drivetime B received in Step S730 or not. If the estimated drive time A issmaller than the estimated drive time B, the processing proceeds to StepS161 and the body control device 109 sets the control mode of the camerabody 100 to the first control mode.

On the other hand, if the estimated drive time A is equal to or largerthan the estimated drive time B in Step S740, the processing proceeds toStep S162. In this case, the body control device 109 considers that thelens data stored in the lens-side ROM 210 in the first interchangeablelens 200 a is damaged due to strong electric impacts such as staticelectricity; and the body control device 109 sets the fourth controlmode, by which driving of the aperture 206 is restricted, to the camerabody 100.

FIG. 12 is a flowchart illustrating lens initialization processingexecuted by the first lens control device 209 a according to the thirdembodiment. Incidentally, the processing in Steps S200 and S210 is thesame as that of the initialization processing (FIG. 6) according to thefirst embodiment, so its explanation has been omitted.

In Step S800, the first lens control device 209 a receives the “aperturedrive time estimation command A” from the body control device 109(corresponding to Step S700 in FIG. 11). In Step S810 in the same manneras in Step S410 in FIG. 8, the first lens control device 209 a estimatesthe drive time of the aperture 206 (or calculates the estimated drivetime A) based on the parameters (the aperture driving amount a and theaperture drive speed v) included in the received aperture drive timeestimation command A and the lens data (the above-described operationexpression (1) and the correction term α) stored in the lens-side ROM210. In Step S820, the first lens control device 209 a sends theestimated drive time A calculated in Step S810 to the body controldevice 109 (corresponding to Step S710 in FIG. 11).

Incidentally, the system may be configured so that the aforementionedoperation expression (2) may be stored as the lens data stored in thelens-side ROM 210 and the drive time of the aperture 206 may beestimated (or the estimated drive time A may be calculated) by usingthis operation expression (2) in Step S810 described above.

From Step S830 to Step S850 in the same manner as from Step S800 to StepS820, the first lens control device 209 a receives the “aperture drivetime estimation command B” from the body control device 109(corresponding to Step S720 in FIG. 11), calculates the estimated drivetime B in the same manner as in Step S810 described above, and sends itto the body control device 109 (corresponding to Step S730 in FIG. 11).

The camera system according to the aforementioned third embodiment canachieve the following operations and effects. (1) The body controldevice 109 sends the two aperture drive time estimation commandsincluding mutually different parameters to the first lens control device209 a, compares the two estimated drive times sent by the first lenscontrol device 209 a in response to the above two commands, and therebyjudges whether the lens data is properly stored in the ROM 210 or not(that is, the safety of the lens data). As a result, it is possible tojudge the safety or stability of the lens data without necessity tostore the body-side data, which is used to judge the safety of the lensdata, in the body-side ROM 112 in the camera body 100 in advance.

Fourth Embodiment

The configuration of a camera system according to a fourth embodiment ofthe present invention is the same as that of the first and secondembodiments, except for some part of it. The difference between thefourth embodiment and the first and second embodiments will be explainedbelow. Incidentally, in the following explanation, the same referencenumerals as those in the first and second embodiments are assigned tothe same elements as those in the first and second embodiments and anexplanation about them has been omitted.

The camera system according to the fourth embodiment calculates theestimated drive time T of the aforementioned aperture 206 by using theoperation expression (1) explained in the aforementioned firstembodiment and uses the calculated estimated aperture drive time as thelens-side judgment data.

The body-side ROM 112 according to the fourth embodiment stores theabove-described operation expression (1) in advance, but does not storethe correction term α data (numerical value data). Regarding thecorrection term α data, the data size of data of only oneinterchangeable lens may possibly become large; and if the correctionterm α data of each of a plurality of interchangeable lenses is to bestored in the body-side ROM 112, it might become necessary to, forexample, add a memory (such as a ROM). Therefore, the system accordingto this fourth embodiment is configured so that the correction term αdata is not stored in the body-side ROM 112 in advance and is receivedfrom the interchangeable lens (the lens-side ROM 210) every time it isneeded (by issuing a correction term α data request command to theinterchangeable lens). Incidentally, when the body control device 109sends the aperture drive time estimation command including the desiredparameters (the aperture driving amount a and the aperture drive speedv) to the lens control device 209 a, it sends the correction term α datarequest command.

After receiving the above-described aperture drive time estimationcommand, the lens control device 209 calculates the estimated drive timeT by using the above-described operation expression (1) and thecorrection term α data which are stored in the lens-side ROM 210. Afteralso receiving the correction term α data request command, the lenscontrol device 209 extracts the correction term α data corresponding tothe desired parameters from among the plurality of pieces of correctionterm α data stored in the lens-side ROM 210. Then, the lens controldevice sends the calculated estimated drive time T and the extractedcorrection term α data (the numerical value data) to the body side.

After receiving the correction term α data from the lens-side ROM 210,the body control device 109 independently estimates (or calculates) theaperture drive time based on the received correction term α data, theaforementioned operation expression (1) (the body-side data) stored inthe body-side ROM 112, and the above-described desired parameters (theaperture driving amount a and the aperture drive speed v) sent to theinterchangeable lens 200 a. Then, the body control device 109 comparesthe estimated drive time T received from the first lens control device209 a with the estimated drive time T calculated by itself; and if thesevalues are identical, the body control device 109 considers that thelens data (the operation expression (1) and the correction term α) isproperly stored in the lens-side ROM 210.

FIG. 13 is a flowchart illustrating initialization processing executedby the body control device 109 according to the fourth embodiment.Incidentally, the processing from Step S100 to S130 is the same as thatof the lens initialization processing (FIG. 5) according to the firstembodiment, so its explanation has been omitted.

If the body control device 109 determines in Step S130 that the firstinterchangeable lens 200 a is mounted, the processing proceeds to StepS900.

In Step S900, the body control device 109 sends a drive time estimationcommand including desired parameters (the aperture driving amount a andthe aperture drive speed v) to the first lens control device 209 a. Theparameters which are set here may be fixed values (specified parameters,that is, a combination of a specified aperture driving amount a and aspecified aperture drive speed v) or different random values which varyevery time the initialization processing is executed (which may be acombination of both random values of the aperture driving amount a andthe aperture drive speed v or a combination of these values, only eitherone of which is a random value).

Also, in this Step S900, the body control device 109 sends a command torequest the aforementioned correction term α data from the first lenscontrol device 209 a. The body control device 109 requests the lenscontrol device 209, through this request command, to provide thecorrection term α data corresponding to a combination of the specifiedaperture driving amount a and the specified aperture drive speed v.

In subsequent Step S910, the body control device 109 receives theestimated drive time T′ from the first lens control device 209 a. Alsoin this Step S910, the body control device 109 receives the numericalvalue data of the correction term α extracted by the lens control device209 a.

In Step S920, the body control device 109 estimates and calculates thedrive time of the aperture 206 in a simplified manner based on thebody-side data (the operation expression (1)) stored in the body-sideROM 112, the parameters for the aperture drive time estimation command(the aperture driving amount a and the aperture drive speed v) sent inStep S900, and the numerical value data of the correction term αacquired from the lens side in Step S910. Then, in Step S930, the bodycontrol device 109 judges whether the estimated drive time T received inStep S910 and the estimated drive time T calculated in Step S920 areidentical or not. If these two values are identical, the processingproceeds to Step S161 and the body control device 109 sets the controlmode of the camera body 100 to the first control mode.

On the other hand, if the estimated drive time T calculated on the bodyside and the estimated drive time T calculated on the lens side are notidentical in Step S930, the processing proceeds to Step S162. In thiscase, the body control device 109 considers that the aforementioned lensdata (at least one of the operation expression (1) and the correctionterm α) stored in the lens-side ROM 210 in the first interchangeablelens 200 a is damaged due to strong electric impacts such as staticelectricity; and the body control device 109 sets the fourth controlmode, by which driving of the aperture 206 is restricted, to the camerabody 100.

FIG. 14 is a flowchart illustrating initialization processing executedby the first lens control device 209 a according to the fourthembodiment. Incidentally, the processing in Steps S200 and S210 is thesame as that of the lens initialization processing (FIG. 6) according tothe first embodiment, so its explanation has been omitted.

In Step S1000, the first lens control device 209 a receives the“aperture drive time estimation command” and the “correction term α datarequest command” from the body control device 109 (corresponding to StepS900 in FIG. 13). In Step S1010 in the same manner as in Step S410 inFIG. 8, the first lens control device 209 a estimates and calculates thedrive time of the aperture 206 (or calculates the estimated drive timeT) based on the parameters (the aperture driving amount a and theaperture drive speed v) included in the received aperture drive timeestimation command and the lens data (the operation expression (1) andthe numerical value data of the correction term α) stored in thelens-side ROM 210. In Step S1020, the first lens control device 209 asends the estimated drive time T calculated in Step S1010 to the bodycontrol device 109 (corresponding to Step S910 in FIG. 13).

The camera system according to the aforementioned fourth embodiment canachieve the following operations and effects. (1) Since the safety orstability of data stored in the lens-side ROM 210 can be judged withoutmaking the body-side ROM 112 retain the correction term α data of theplurality of interchangeable lenses, it is possible to simplify thehardware configuration of the camera body side.

The following variations are also within the scope of the presentinvention and one or more variations can be combined with theaforementioned embodiments.

(Variation 1)

Each of the aforementioned embodiments described the example where thepresent invention is applied to the lens data about driving of theaperture 206 which can be moved so as to change the size of the openingthrough which the light flux passes; however, the present invention canalso be applied to other driven members. For example, the presentinvention may be applied to lens data about driving of the focusing lens204 which can be moved in a direction of the optical axis X of theoptical system. Specifically speaking, the first interchangeable lens200 a may be configured so as to be capable of estimating the drive timeof the focusing lens 204 and the lens data about driving of the focusinglens 204 may be stored in the lens-side ROM 210. Furthermore, a shakecorrection lens that corrects image blurs of a subject image (lenscapable of moving in a direction including a component perpendicular tothe optical axis X) can be added to the first interchangeable lens 200 aand the present invention can be applied to this shake correction lens.

(Variation 2)

In the first embodiment, only some part of the lens data may begenerated as the lens-side judgment data and sent to the camera body 100without sending all pieces of the lens data to the camera body 100 asthe lens-side judgment data. For example, if the lens data includes anoperation expression to estimate the drive time of the aperture 206 andits correction term, only the operation expression may be generated andsent as the lens-side judgment data. In this case, all what is needed isto store only the operation expression in the body-side ROM 112 in thecamera body 100.

Furthermore, the lens-side judgment data may be data other than theoperation expression or the correction term of the aforementionedestimated drive time. For example, it may be a parameter other than thecorrection term given to the operation expression of the estimated drivetime or may be data representing a unit of drive control of the aperture206 (driving unit of the aperture drive unit 208) (for example, thenumber of aperture drive steps as indicated by data “1 LSB”).Furthermore, it may be data representing whether the lens data is storedin the lens-side ROM 210 or not.

(Variation 3)

Timing to store the body-side judgment data in the body-side ROM 112 inthe camera body 100 may be, for example, when the relevant camera body100 is manufactured or when the relevant interchangeable lens is mountedon the camera body 100 for the first time. In the latter case, normallens-side judgment data is stored at the first time the interchangeablelens is mounted; and then every time the interchangeable lens ismounted, the lens data judgment is performed.

(Variation 4)

In each of the aforementioned embodiments, the lens data judgment isperformed during the initialization processing; however, the presentinvention is not limited to such embodiment. For example, the lens datajudgment may be performed every certain period of time when the digitalcamera 1 is in the power-on state; or the lens data judgment may beperformed every time photographing is performed.

(Variation 5)

When the two estimated drive times are compared in the secondembodiment, these two values should not necessarily be strictlyidentical. For example, an error may occur in these two estimated drivetimes depending on floating-point arithmetic precision. So, if thedifference between the two estimated drive times is equal to or lessthan a specified threshold value, they may be determined to beidentical.

(Variation 6)

In the second embodiment, the lens control device 209 a performssimplified calculation of the aperture drive time by using the commonoperation expression; however, the system may be configured so that thesimplified aperture drive estimated time T′ is calculated without usingan operation expression like the one mentioned above, but using a table(for example, a two-dimensional table whose parameters are the aperturedriving amount a and the aperture drive speed v). In this case, the bodycontrol device 109 should be configured to include a table of the samecontent as this calculation table.

(Variation 7)

In each of the aforementioned embodiments when the fourth control modeis set (when it is determined that the lens data is not properlystored), the photographing operation and other processing are executedwithout sending the aperture drive command to the first lens controldevice 209 a and by keeping an opening diameter of the aperture 206fixed; however, different operation from that of each embodiment may beadopted when the lens data is not properly stored. For example, drivingof the aperture may be performed without designating the drive speed ofthe aperture 206 (by sending the aperture drive command which does notinclude the parameter for the drive speed) (that is, the setting of the“second control mode” in the aforementioned embodiments may be set), orpower supply to the interchangeable lens may be stopped or photographingusing the relevant interchangeable lens may be prohibited.

(Variation 8)

In place of the simplified aperture drive time estimation command sentby the body control device 109 when performing the judgment in thesecond embodiment, a command same as the aperture drive time estimationcommand used for photographing may be used. Specifically speaking, ifthe operation expression (1) and correction term α same as the operationexpression (1) and the correction term α stored in the lens-side ROM 210in the interchangeable lens 200 mounted on the body mount unit arestored in the body-side ROM 112 in advance, the same judgment as that inthe second embodiment can be performed without separately using thesimplified common operation expression (or without storing it in theROMs of both sides).

(Variation 9)

In each of the aforementioned embodiments, the lens control device 209 acalculates the aperture drive time T by using the operation expression(1) and the correction term α; however, the system may be configured sothat the aperture drive estimated time T is calculated without using anoperation expression like the one mentioned above, but by using a table(for example, a two-dimensional table whose parameters are the aperturedriving amount a and the aperture drive speed v and in which thecorrection term α is added in advance to numerical values in the table).

(Variation 10)

The aforementioned third embodiment is configured so that if theestimated drive time as a response to the aperture drive time estimationcommand A is smaller (or shorter) than the estimated drive time as aresponse to the aperture drive time estimation command B, it isdetermined that the first lens control device 209 a has successfullyestimated the drive time of the aperture 206 (that is, the lens data isproperly stored in the lens-side ROM 210). However, the judgment of thissize relation may be reversed. Specifically speaking, the body controldevice 109 may set the aperture driving amount of the aperture drivetime estimation command A to be larger than the aperture driving amountof the aperture drive time estimation command B and then judge whetherthe first estimated drive time is larger than the second estimated drivetime or not (if the first estimated drive time is larger than the secondestimated drive time, that means the first lens control device 209 a hassuccessfully estimated the drive time of the aperture 206, that is, thelens data is properly stored in the lens-side ROM 210).

(Variation 11)

The above-described third embodiment and Variation 10 are configured sothat the first lens control device 209 a calculates the estimated drivetimes respectively in response to the aperture drive time estimationcommands A and B from the body control device 109 and sends thecalculated estimated drive times to the body control device 109.Furthermore, the body control device 109 is configured to compare thetwo estimated drive times received from the lens control device 209 aand identifies which one is larger/smaller than the other. However, thebody control device 109 does not necessarily have to receive the twoestimated drive times or perform the comparison operation, but all whatis needed is to find the size relation between the two estimated drivetimes (Time A and Time B) (“Time A<Time B” in the third embodiment and“Time A>Time B” in Variation 10). Therefore, the system may beconfigured so that after calculating the two estimated drive times, thelens control device 209 a itself compares the size relation between thetwo estimated drive times and sends information indicating thecomparison result (information indicating the size relation between thetwo calculated estimated drive times, for example, informationindicating “Time A<Time B” in the third embodiment and informationindicating “Time A>Time B” in Variation 10) to the body control device109.

(Variation 12)

In the above-described second embodiment, the body control device 109also independently estimates the aperture drive time in a simplifiedmanner by using the aforementioned “common operation expression.”However, instead of performing the simplified estimation (calculation)using the aforementioned “common operation expression,” the body controldevice 109 may calculate the aforementioned “simplified estimated drivetime T′” by using table information (described later) (the body-sidedata) stored in the body-side ROM 112 in advance. Specifically speaking,the table information (the body-side data) composed of desiredparameters (combinations of a desired aperture driving amount a and adesired aperture drive speed v) and the “simplified estimated drive timeT′” corresponding to each of such combinations may be stored in thebody-side ROM 112. Then, the body control device 109 selects the“simplified estimated drive time T′” which is to be used as a comparisontarget corresponding to the desired parameters (the aperture drivingamount a and the aperture drive speed v) to be sent as a command to thelens side, from the table information. Then, the body control device 109compares the “simplified estimated drive time T′” sent from the lenscontrol device 209 a with the “simplified estimated drive time T′”selected from the aforementioned table information. Subsequentprocessing is the same as that in the aforementioned second embodiment.As a result, the body control device 109 can compare the “simplifiedestimated drive times T′” without performing calculation by using thecommon operation expression.

Variation 12 which is a variation of the second embodiment will beexplained below with reference to FIG. 15 and FIG. 16. Incidentally, inthe following explanation, the same reference numerals as those in thesecond embodiment are assigned to the same elements as those in thesecond embodiment and an explanation about them has been omitted.

FIG. 15 shows an example of table information stored in the body-sideROM 112. The body-side ROM 112 stores table information 10 instead ofthe “simplified operation expression (2) “T′=a/v” described earlier. Thetable information 10 contains a plurality of sets (five sets in FIG. 16)of parameters including the aperture driving amount a and the aperturedrive speed v, which are associated with simplified estimated drive timeT′. In the following explanation, this set will be referred to as theparameter set (the body-side data). Incidentally, simplified estimateddrive times T1′ to T5′ indicated in FIG. 15 are, for example, valueseach calculated in advance by assigning one of the aperture drivingamounts a1 to a5 and one of the aperture drive speeds v1 to v5 which areindicated in FIG. 15 to the aforementioned “simplified operationexpression (2)” stored in advance in, for example, a computer installedat a factory manufacturing this camera system. This table information isstored in the body-side ROM 112 at the time of, for example, factoryshipment.

FIG. 16 is a flowchart illustrating initialization processing executedby the body-side control device 109 according to Variation 12.Incidentally, the operation from Step S100 to S130 is the same as thatof the flowchart shown in FIG. 9, so its explanation has been omitted.

When the first interchangeable lens 200 a is mounted on the camera body100, the body-side control device 109 makes a negative judgment in StepS130 and the processing proceeds to Step S1090. In Step S1090, the bodycontrol device 109 selects any one of the parameter sets from the tableinformation 10 stored in the body-side ROM 112.

In subsequent Step S1100, the body control device 109 sends thesimplified aperture drive time estimation command to the first lenscontrol device 209 a. This command contains the aperture driving amountand the aperture drive speed of the parameter set selected in StepS1090. For example, if the first set is selected in Step S1090, thecommand sent in Step S1100 contains the aperture driving amount a1 andthe aperture drive speed v1.

Next in Step S510, the body control device 109 receives the simplifiedestimated drive time T′ calculated by the first lens control device 209a from the first lens control device 209 a. This estimated drive time T′is a value calculated by the first lens control device 209 a byassigning the aperture driving amount and the aperture drive speed,which are contained in the command sent in Step S1100, to theaforementioned simplified operation expression (2). For example, if thefirst set is selected in Step S1090, the first lens control device 209 acalculates the simplified estimated drive time T′ by using the aperturedriving amount a1 and the aperture drive speed v1.

Then, in Step S1120, the body control device 109 acquires the simplifiedestimated drive time T′ included in the parameter set selected in StepS1090 from the table information 10. For example, if the first set isselected in Step S1090, the simplified estimated drive time T1′ includedin that first set is acquired in Step S1120. Subsequently, in StepS1130, the body control device 109 judges whether the simplifiedestimated drive time T′ received in Step S510 and the simplifiedestimated drive time T′ (for example, T1′) acquired in Step S1120 areidentical or not. If these two values are identical, the processingproceeds to Step S161 and the body control device 109 sets the controlmode of the camera body 100 to the first control mode mentioned earlier.On the other hand, if the two values are not identical in Step S1130,the processing proceeds to Step S162 and the body control device 109sets the aforementioned fourth control mode to the camera body 100.

Incidentally, in this Variation 12, the operation of the first lenscontrol device 209 a is the same as that illustrated in the flowchart ofFIG. 10, so that its explanation has been omitted.

Meanwhile, in Variation 12 described above, the simplified operationexpression (2) “T′=a/v” is used as an operation expression when thesimplified estimated drive times T1′ to T5′ in the table information 10are calculated in advance and when the simplified estimated drive timeT′ to be received from the interchangeable lens is calculated at theinterchangeable lens in Step S510 of FIG. 16. However, it is alsopossible to employ the configuration so as to use the aforementionedoperation expression (1) “T=a/v+α (T=α+a/v)” instead of this simplifiedoperation expression (2).

Variation 12 has described the example in which the table information 10includes the five parameter sets, that is, the first to fifth sets;however, the number of the parameter sets is not limited to five and maybe more or less than five. For example, the table information 10 mayinclude only one parameter set. However, if two or more parameter setsare included in the table information 10, the two or more parameter setscan be sequentially sent to the interchangeable lens and the simplifiedestimated drive time T′ can be checked for each of the parameter sets,so that the safety check effect of the lens data stored in the lens-sideROM 210 can be enhanced. Therefore, the table information 10 shouldpreferably include a plurality of parameter sets.

(Variation 13)

In each of the aforementioned embodiments and each of the variationsregarding control at the camera body, the body control device performsthe judgment operation only once (for example, Step S160 in FIG. 5, StepS530 in FIG. 9, and Step S1130 in FIG. 15) to judge whether to set theaforementioned first control mode or to set the aforementioned fourthcontrol mode. The camera body may be configured to perform this judgmentmore than once. Alternatively, this judgment operation may be performedonce and the first or fourth control mode may be set, and then thisjudgment may be performed again at specified timing (for example, whenre-judgment is requested or a specified period of time has elapsed sincethe last judgment). Furthermore, this judgment may be performedrepeatedly in every specified cycle.

Incidentally, when this re-judgment is to be performed, the camera bodyrequests the interchangeable lens to send the lens-side judgment data tothe camera body again and the camera body operates to prepare the datafor comparison with the lens-side judgment data again. Referring to theexample of FIG. 15, the operation is performed to repeat the operationfrom Step S1090 to Step S1130 again.

The present invention is not limited to the above-described embodimentsunless features of the present invention are impaired; and otherembodiments which are conceivable within the range of technical ideas ofthe present invention are also included to within the scope of thepresent invention.

The disclosure of the following priority application is hereinincorporated by reference: Japanese Patent Application No. 2012-191979filed on Aug. 31, 2012; and Japanese Patent Application No. 2012-269590filed on Dec. 10, 2012.

REFERENCE SIGNS LIST

-   -   100 camera body; 101 body mount unit; 102, 202 pluralities of        electric contacts; 103 quick return mirror; 104 image sensor,        105 sub-mirror; 106 focal point detector, 107 finder screen; 108        pentaprism; 109 body control device; 110 ocular lens; 111 body        side aperture drive unit; 112, 210 ROMs; 120 release switch; 200        a first interchangeable lens; 200 b second interchangeable lens;        200 c third interchangeable lens; 201 lens mount unit; 204        focusing lens; 206 aperture; 207 lens drive unit; 208 aperture        drive unit; 209 a first lens control device; 209 b second lens        control device; and 209 c third lens control device.

1. An interchangeable lens, comprising: a mount on which a camera bodycan be mounted; a driven member; a driver configured to drive the drivenmember, a storage device that stores lens data related to driving of thedriven member by the driver; and a transmitter that sends lens-sidejudgment data, based on which whether the lens data is properly storedin the storage device can be judged at the camera body, to the camerabody even when the lens data is properly stored in the storage device.2. The interchangeable lens according to claim 1, wherein: the lens-sidejudgment data is generated based on the lens data stored in the storagedevice.
 3. The interchangeable lens according to claim 1, furthercomprising: a processor configured to estimate drive time required forthe driver to drive the driven member by a desired driving amount at adesired drive speed based on the lens data stored in the storage device.4. The interchangeable lens according to claim 3, wherein: thetransmitter sends the drive time estimated by the processor as thelens-side judgment data to the camera body.
 5. The interchangeable lensaccording to claim 4, wherein: the lens data includes an operationexpression to calculate the drive time by using at least the desireddrive speed and the desired driving amount; and the processor estimatesthe drive time by calculation processing that uses the operationexpression.
 6. The interchangeable lens according to claim 5, wherein:the lens data includes a simple operation expression to calculate thedrive time by using only the desired drive speed and the desired drivingamount; and the processor estimates the drive time by calculationprocessing that uses the simple operation expression.
 7. Theinterchangeable lens according to claim 5, wherein: the processorcalculates the drive time by changing at least one of values of thedrive speed and the driving amount every time the calculation isperformed.
 8. The interchangeable lens according to claim 5, wherein:the storage device stores the lens data including at least one of theoperation expression of the drive time and correction term data given tothe operation expression of the drive time; and the transmitter sends atleast part of the correction term data as data related to the lens-sidejudgment data to the camera body.
 9. The interchangeable lens accordingto claim 5, wherein: the processor calculates a plurality of drive timesby executing the calculation processing to calculate the drive timeevery time the processor receives a combination of the desired drivespeed and the desired driving amount; and the transmitter sendsinformation about the plurality of drive times calculated by thecalculation processing as the lens-side judgment data to the camerabody.
 10. The interchangeable lens according to claim 3, wherein: thetransmitter sends at least part of the lens data stored in the storagedevice as the lens-side judgment data to the camera body.
 11. Theinterchangeable lens according to claim 10, wherein: the storage devicestores the lens data including at least one of an operation expressionof the drive time and a parameter given to the operation expression ofthe drive time.
 12. The interchangeable lens according to claim 1,further comprising: an optical system including the driven member,wherein: the driven member includes any one of a member capable ofmoving along an optical axis of the optical system, a member capable ofmoving in a direction including a component perpendicular to the opticalaxis, and a member capable of moving so as to change a size of anopening through which a light flux passes.
 13. A camera body comprising:a mount on which an interchangeable lens including a driven member and astorage medium storing lens data related to driving of the driven membercan be mounted; a receiver that receives lens-side judgment data, basedon which whether the lens data is properly stored in the storage mediumor not can be judged, from the interchangeable lens even when the lensdata is properly stored in the storage medium; and a processorconfigured to judge whether the lens data is properly stored in thestorage medium or not, based on the lens-side judgment data receivedfrom the receiver.
 14. The camera body according to claim 13, wherein:the receiver receives the lens-side judgment data generated based on thelens data stored in the storage medium.
 15. The camera body according toclaim 13, wherein: the receiver receives drive time, which is requiredto drive the driven member by a desired driving amount at a desireddrive speed and is estimated by the interchangeable lens based on thelens data, as the lens-side judgment data from the interchangeable lens.16. The camera body according to claim 15, further comprising: a storagedevice that stores body-side data to be compared with the lens-sidejudgment data received from the receiver, wherein: the processorperforms the judgment based on the body-side data and the lens-sidejudgment data received from the receiver.
 17. The camera body accordingto claim 13, wherein: the receiver receives at least part of the lensdata stored in the storage medium as the lens-side judgment data fromthe interchangeable lens.